# Is HR 5171 a Spectroscopic Binary or a Symbiotic?

Is HR 5171, the largest yellow star in the galaxy a symbiotic star where one feeds off the other? Or is it a spectroscopic binary where its only possible to determine that there are two stars by spectral analysis?

Will the smaller be consumed by the larger one as was in the possible case of BP Piscium? Or is the smaller one being born?

Is the star both, one or the other or neither?

I looked at Simbad but it only calls a Double or Multiple Star System. That is too vague for me. Calling it a Close Contact Binary is also too vague. I know they call it an EBS.

If anyone wants an idea of the star, visit the following artist's impression.

• I slightly edited your question to make it easier to read, hope you agree with my suggestions. Also +1 :-) – B--rian Jan 1 at 14:18

Modeling the light curve with the NIGHTFALL program provides clear evidence that the system is a contact or possibly over-contact eclipsing binary. A total current system mass of $$39^{+40}_{-22}$$ solar mass and a high mass ratio $$q>10$$ is inferred for the system. The low-mass companion of $${\rm HR5171 A}$$ is very close to the primary star that is embedded within its dense wind. Tight constraints on the inclination and vsini of the primary are lacking, which prevents us from determining its influence precisely on the mass-loss phenomenon, but the system is probably experiencing a wind Roche-Lobe overflow.